Remove dependencies between analysers

[jbodah]

I took a brief pass at trying to add an --only option to restrict certain analysers from running, but it seems that there is some dependencies between the analysers during a run that I fully grok yet.

For reference, my initial attempt at adding an --only option https://github.com/jbodah/rubycritic/commit/8d54cea734bc4bc1fd86f2130dd24a899e76d275

[jbodah]

Note "between analysers" is not really the right choice of words. It's really that the run was expecting something that wasn't there when I only used the Flay analyser